NAME

Statistics::Basic::StdDev - find the standard deviation of an array

SYNOPSIS

Invoke it this way:

my $stddev = stddev(1,2,3);

Or this way:

my $v1  = vector(1,2,3);
my $std = stddev($v1);

And then either query the values or print them like so:

print "The stddev of $v1: $std\n";
my $sq = $std->query;
my $s0 = 0+$std;

Create a 20 point "moving" stddev like so:

my $sth = $dbh->prepare("select col1 from data where something");
my $len = 20;
my $std = stddev();
   $std->set_size($len);

$sth->execute or die $dbh->errstr;
$sth->bind_columns( my $val ) or die $dbh->errstr;

my $count = $len;
while( $sth->fetch ) {

    $std->insert( $val );
    if( -- $count <= 0 ) {
        print "StdDev: $std\n";
    }
}

The full details are probably in the base module. If you have questions, just let me know.

AUTHOR

Paul Miller <jettero@cpan.org>

SEE ALSO

perl(1), Statistics::Basic